During transmission of transport streams, such as digital television broadcasts, certain messages may be included within the transport stream to provide signals or instructions to downstream components. For example, when a television broadcaster broadcasts a Single Program Transport Stream (SPTS) of television content, the SPTS may include various types of Society of Cable Telecommunications Engineers (SCTE) messages, which may be multiplexed within a designated packet identifier in the stream. An example of a SCTE message is an SCTE-35 message that indicates that a commercial or other message (e.g., advertisement, public service announcement, etc.) is upcoming within the transport stream. Such messages may be used by satellite systems, cable systems, over-the-top (OTT) systems, etc., to perform local advertisement insertion and other related functions.
However, within multi-layer transmission architectures, the possibility exists that such messages within the transport stream may be stripped out by intermediate transmitters. For instance, when a national television broadcast passes through local affiliate broadcasters and/or other intermediary transcoders, SCTE-35 transport packets might be stripped out and not preserved within the transport stream as it continues to further downstream components.
Thus, a need exists to preserve SCTE-35 messages and/or various additional types of message data, which are transmitted from a top-level broadcaster to the various uplink centers and re-transmitters that receive the transport single indirectly via one or more intermediate transmitters.